Unusual deep-sea sea cucumbers

This 12 March 2020 video says about itself:

The sea pig Scotoplanes is one of the most abundant animals found on the abyssal plain. These unusual sea cucumbers walk around the seafloor on elongated tube feet which keep them from sinking into the soft mud. They are deposit feeders, digging decaying pieces of algae and animals out of the mud using ten tentacles surrounding their mouth. Long, whip-like sensory organs, called papillae, help them find nutrient-rich food falling down from shallower waters. Their populations are directly influenced by what is happening at the surface of the ocean. For example, large groups of sea pigs can be found feasting near sunken whale carcasses and other food falls on the seafloor.

In 2016, MBARI documented a surprising relationship between sea pigs and king crabs (Neolithodes diomedeae). During a survey of an open area of muddy seafloor, 96 percent of the juvenile crabs were observed clinging to the undersides of Scotoplanes sea cucumbers, presumably for protection from predators. We don’t yet know how the hosts may be benefiting from their little hitchhikers. Our researchers are still digging up new facts about the sea pig.

Common name: Sea pig
Scientific name: Scotoplanes
Reported depth range: 1,000 meters – 6,000+ meters (3,300 – 19,500+ feet)
Size: to 17 centimeters (6.5 inches)

Editor: Ted Blanco
Writer: Kyra Schlining
Production team: Kyra Schlining, Susan von Thun, Nancy Jacobsen Stout